Major Description
We currently have no data model for Samza jobs. As a result, we have really hacky code in JsonHelpers to handle (de)serializing job/container/task information between the job coordinator and its SamzaContainers.
We should provide a proper data model for Samza jobs, which includes a Job, Container, and Task. The objects should contain relevant data that the job coordinator and SamzaContainer need. These classes should be written in Java, and use proper Jackson annotations to allow for easy (de)serialization.